1. Field of the Invention
The invention relates to an art of mounting a concentrated winding coil unit on a stator of a motor, and to an art of making an improvement in automatic assembly properties.
2. Description of the Related Art
In recent years, as is the case with hybrid vehicles, the number of cases in which a large motor used for driving is mounted on a vehicle has been increasing. In a stator employed in such an on-vehicle motor, a plurality of concentrated winding coil units, with coils wound therearound, are fitted on a stator core. Coil terminals provided on the concentrated winding coil units are inserted into end terminals on a wire connection terminal side provided on the stator, and are connected thereto respectively by a caulking finishing machine or the like.
In the case where the concentrated winding coil units as described above are mounted on the stator to manufacture the motor, there is a problem of the inferiority in automatic assembly properties. Studies have recently been conducted also on arts of making an improvement in such automatic assembly properties. An art regarding a method of manufacturing a motor with high automatic assembly properties is disclosed in Japanese Patent Application Publication No. 2007-215356 (JP-A-2007-215356). While a coil unit is inserted into an end terminal of a wire connection terminal, a coil terminal is guided by a guide member. The guide member is equipped with a floating mechanism, and can be freely positioned. A pair of guide-equipped chuck members coupled to an air cylinder sandwich the end terminal, and the coil terminal, which is guided by the guide member, is inserted.
In manufacturing the concentrated winding coil unit, the concentrated winding coil unit is designed such that the coil terminal is more or less accurately positioned. However, due to a construction in which a lead wire is pulled out from the coil unit, there is a limit to the enhancement of the accuracy. Thus, the guide member is equipped with the floating mechanism to make it possible to absorb the dispersion in a lateral direction. By using the guide member equipped with the floating mechanism to assemble the stator as described above, an improvement in automatic assembly properties in assembling the coil unit with the stator can be achieved.
However, the art disclosed in Japanese Patent Application Publication No. 2007-215356 (JP-A-2007-215356) is considered to have the following problem. In the art disclosed in Japanese Patent Application Publication No. 2007-215356 (JP-A-2007-215356), the guide member is equipped with the floating mechanism to cope with the lateral dispersion of lead wire protruding from the coil unit. However, the lead wire disperses not only in the lateral direction but also in a vertical direction. It is difficult to absorb this dispersion with the aforementioned construction.
Originally, tight restrictions are imposed on the dimension of the on-vehicle motor, and it is desirable to form the on-vehicle motor in a size as small as possible. Thus, in connecting the coil unit to a bus bar provided on the stator core, the lead wire protruding from the coil unit and the end terminal formed on the bus bar tend to be formed in a small size. This reduction in the size of the motor leads to a deterioration in the assembly properties in assembling the coil unit with the stator core, and constitutes a limiting factor for automation. In particular, the mounting of the lead wire protruding from the coil unit on the end terminal is likely to cause dispersion and hence gives rise to a problem. It is possible to reduce the dispersion in the lateral direction by providing the floating mechanism laterally movably as disclosed in Japanese Patent Application Publication No. 2007-215356 (JP-A-2007-215356). However, since there is only a small room in the vertical direction, it is difficult to ensure a clearance for absorbing dispersion through the method disclosed in Japanese Patent Application Publication No. 2007-215356 (JP-A-2007-215356).